AUTOMATIC RETURN VALVE Russian patent published in 1995 - IPC

FIELD: drilling. SUBSTANCE: valve has casing 1 with seat 2. Disk valve 8 with rod 4 is put on the seat. Rod 4 passes through opening in crossbar 5 installed in casing 1. Washing 6 is secured on the side of rod 4 being opposite to valve 3. A spring is installed between the washer and crossbar. A sleeve is put on rod 4 on the side of the washer. Radial bores are drilled in lugs of the crossbar, with stops loaded by springs 11 installed in the bores. Other sides of the stops are rested on casing 1. The stops wedge rod 4 when specified pressures have been achieved, allowing one to clean turbodrill and to wash out the well or to do other operations needed when the valve is open. The structure is operated as return valve in other cases. EFFECT: turbodrill cleaning. 2 dwg